France prop Pieter De Villiers has denied taking drugs despite testing positive for cocaine and ecstasy just before Christmas.

"I have always been true to my sport and my club. I never took drugs or doping products," the 30-year-old De Villiers told a news conference in Paris on Wednesday.

"I'm going to ask for a 'B' test."

I drank a lot of beers in several pubs and I was sick as never before - maybe I was trapped Pieter De Villiers

French Rugby Federation president Bernard Lapasset confirmed on Wednesday that the South African-born forward had failed a drugs test on 18 December.

But the Stade Francais star indicated he may have taken the drugs unwittingly during a post-match night out in Paris.

"How did it happen? My mind boggles. I can't eat anymore, I can't sleep," De Villiers said.

"The only thing I remember is a post-match party after a game against Harlequins on 14 December.

"I drank a lot of beers in several pubs. I was sick as never before. Maybe I was trapped.

"I am going to ask for a 'B' test. My only mistake was to have fun after a rugby game."

He faces an uncertain future if this is true France coach Bernard Laporte

De Villiers has already been dropped from the side to play England in the Six Nations championship opener at Twickenham on 15 February.

But the player, capped 29 times by France, could face a longer spell on the sidelines.

Under International Rugby Board rules, a player whose A sample has tested positive is suspended until his B sample has been tested.

"This case is going to hurt French rugby very badly," said Lapasset.

"Last night (Tuesday) when we found out about it, we thought it was a joke. We could not have imagined worse.

"The first feeling we had was of total incomprehension, but then we realised there was some proof."

I think it is an accident and I will be happy to play with him France captain Fabien Galthie

French team manager Joe Maso said last month that any player who used drugs would be banned for life, although a three-month suspension is the more likely scenario.

Christian Califano, whose last international cap was back in June 2001, is set to return to France's 22-man squad in place of De Villiers.

But winger David Bory is also out of the England game because of a torn calf muscle.